阅读说明：本技术 一种化合物及其应用 (Compound and application thereof ) 是由 孙恩涛 方仁杰 刘叔尧 吴俊宇 于 2020-05-06 设计创作，主要内容包括：本发明提供了一种化合物及其应用,所述化合物具有式I结构,所述化合物用作有机电致发光器件中的电子传输层的材料；所述有机电致发光器件包括第一电极、第二电极以及在所述第一电极和第二电极之间的有机层,所述有机层中含有所述化合物中的任意一种或至少两种组合；该化合物具有较高的电子注入和迁移性能；将该化合物作为电子传输层材料用于有机电致发光器件中,能够提高器件的发光效率,并降低器件的启动电压。(The invention provides a compound and application thereof, wherein the compound has a structure shown in a formula I and is used as a material of an electron transport layer in an organic electroluminescent device; the organic electroluminescent device comprises a first electrode, a second electrode and an organic layer between the first electrode and the second electrode, wherein the organic layer contains any one or at least two combinations of the compounds; the compound has high electron injection and migration performance; the compound is used as an electron transport layer material for an organic electroluminescent device, so that the luminous efficiency of the device can be improved, and the starting voltage of the device can be reduced.)

1. A compound having the structure of formula (I):

in the formula (I), R_aIndependently selected from deuterium, halogen, cyano, nitro, hydroxyl, chain alkyl of C1-C12, alkoxy of C1-C12, cycloalkyl of C3-C12, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, and R is_aIs connected with a mother ring by a single bond, and the mother ring is pyrido triazole;

in the formula (I), b is an integer of 0 to 4;

in the formula (I), L is any one selected from a single bond, chain alkylene of C1-C12, cycloalkylene of C3-C12, substituted or unsubstituted C6-C30 arylene and substituted or unsubstituted C3-C30 heteroarylene;

in the formula (I), Ar is any one selected from cyano, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl;

R_ain L and Ar, the substituted groups are respectively and independently selected from one or the combination of at least two of halogen, cyano, nitro, hydroxyl, C1-C12 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 condensed ring heteroaryl.

2. A compound of claim 1, wherein R is_aIndependently selected from any one of substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl;

preferably, said R is_aIndependently selected from any one of substituted or unsubstituted C6-C40 aryl.

3. A compound of claim 2, wherein R is_aIndependently selected from any one of the following substituted or unsubstituted groups:

wherein denotes a ligation site;

preferably, said R is_aIndependently selected from any one of the following groups:

4. the compound of claim 1, wherein b is 0 or 1.

5. The compound of claim 1, wherein L is selected from any one of substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C3-C30 heteroarylene;

preferably, L is selected from substituted or unsubstituted C6-C30 arylene;

preferably, the L is selected from any one of the following substituted or unsubstituted groups:

wherein denotes a ligation site;

preferably, the L is selected from any one of the following substituted or unsubstituted groups:

6. the compound of claim 1, wherein Ar is selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

preferably, Ar is selected from any one of substituted or unsubstituted C3-C30 heteroaryl;

preferably, Ar is selected from any one of substituted or unsubstituted C3-C30 electron-deficient heteroaryl.

7. The compound of claim 6, wherein Ar is selected from any one of (Hy-1) to (Hy-4) groups:

(Hy-1) wherein Y is as defined above₁、Y₂、Y₃、Y₄、Y₅And Y₆Each independently selected from the group consisting of CR or N atoms, and Y₁、Y₂、Y₃、Y₄、Y₅And Y₆At least one of them is an N atom;

(Hy-2) wherein Z is₁、Z₂、Z₃、Z₄And Z₅Each independently selected from the group consisting of CR or N atoms, and Z₁、Z₂、Z₃、Z₄And Z₅At least one of them is an N atom;

(Hy-3) wherein Z is₆、Z₇、Z₈、Z₉、Z₁₀、Z₁₁、Z₁₂And Z₁₃Each independently selected from the group consisting of CR or N atoms, and Z₆、Z₇、Z₈、Z₉、Z₁₀、Z₁₁、Z₁₂And Z₁₃At least one of them is an N atom;

(Hy-4) wherein Y is as defined above₇、Y₈、Y₉、Y₁₀、Y₁₁、Y₁₂And Y₁₃Each independently selected from the group consisting of CR or N atoms, and Y₇、Y₈、Y₉、Y₁₀、Y₁₁、Y₁₂And Y₁₃At least one of them is an N atom;

r is independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, chain alkyl of C1-C12, alkoxy of C1-C12, cycloalkyl of C3-C12, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, wherein the substituted group is selected from any one of halogen, chain alkyl of C1-C10, cycloalkyl of C3-C10, alkenyl of C2-C10, alkoxy of C1-C6, thioalkoxy of C1-C6, monocyclic aryl of C6-C30, condensed ring aryl of C10-C30, monocyclic heteroaryl of C3-C30 and fused ring heteroaryl of C6-C30;

wherein denotes the attachment site.

8. The compound of claim 7, wherein Ar is selected from any one of the following substituted or unsubstituted groups:

wherein denotes a ligation site;

preferably, Ar is selected from any one of the following groups:

9. the compound of claim 1, wherein Ar is selected from cyano or

10. The compound of claim 1, wherein the compound has the structure of formula (I-1):

in the compound C1-C270 with the structure of formula (I-1), R_aL and Ar are selected from the group shown in Table 1:

TABLE 1

Wherein R in position 1^aIs denoted by R^aSubstituted in the 1-position of the mother ring by a radical selected from, R in the 2-position^aIs denoted by R^aSubstituted in the 2-position of the mother ring by a radical selected from, R in the 3-position^aIs denoted by R^aSubstituted in the radical selected from the 3-position of the mother ring, R in the 4-position^aIs denoted by R^aSubstituted at the 4-position of the parent ring with a group selected from;

denotes the site of attachment to the mother loop.

11. Use of a compound according to any of claims 1-10 as a material for an electron transport layer in an organic electroluminescent device.

12. An organic electroluminescent device comprising a first electrode, a second electrode and an organic layer between the first electrode and the second electrode, wherein the organic layer contains the compound according to any one of claims 1 to 10.

Technical Field

The invention relates to the technical field of organic electroluminescence, in particular to a compound and application thereof, and especially relates to a compound and application thereof, and an organic electroluminescent device containing the compound.

Background

Organic Light Emission Diodes (OLED) devices are a kind of devices with sandwich-like structure, which includes positive and negative electrode films and Organic functional material layers sandwiched between the electrode films. And applying voltage to the electrodes of the OLED device, injecting positive charges from the positive electrode and injecting negative charges from the negative electrode, and transferring the positive charges and the negative charges in the organic layer under the action of an electric field to meet for composite luminescence. Because the OLED device has the advantages of high brightness, fast response, wide viewing angle, simple process, flexibility and the like, the OLED device is concerned in the field of novel display technology and novel illumination technology. At present, the technology is widely applied to display panels of products such as novel lighting lamps, smart phones and tablet computers, and further expands the application field of large-size display products such as televisions, and is a novel display technology with fast development and high technical requirements.

With the continuous advance of OLEDs in both lighting and display areas, much attention has been paid to the research on their core materials. This is because an efficient, long-lived OLED device is generally the result of an optimized configuration of the device structure and various organic materials, which provides great opportunities and challenges for chemists to design and develop functional materials with various structures. Common functionalized organic materials are: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, and light emitting host materials and light emitting objects (dyes), and the like.

The OLED light-emitting device with lower driving voltage, better light-emitting efficiency and longer service life is prepared, the performance of the OLED device is continuously improved, the structure and the manufacturing process of the OLED device are required to be innovated, and the photoelectric functional material in the OLED device is required to be continuously researched and innovated, so that the functional material with higher performance is prepared. Based on this, the OLED material industry has been working on developing new organic electroluminescent materials to achieve low starting voltage, high luminous efficiency and better lifetime of the device.

In order to further satisfy the continuously increasing demand for the photoelectric properties of OLED devices and the energy saving demand of mobile electronic devices, new and efficient OLED materials need to be continuously developed, wherein the development of new electron transport materials with high electron injection capability and high mobility is of great significance.

Disclosure of Invention

In view of the deficiencies of the prior art, it is an object of the present invention to provide a compound having the structure of formula (I):

in the formula (I), R_aIndependently selected from deuterium, halogen, cyano, nitro, hydroxyl, chain alkyl of C1-C12, alkoxy of C1-C12, cycloalkyl of C3-C12, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, and R is_aThe pyridine triazole is connected with a mother ring through a single bond, the mother ring is pyridine triazole, if the mother ring appears later, the indication meaning is the same as that of the mother ring, and detailed description is omitted;

in the formula (I), b is an integer of 0-4 (such as 0, 1, 2, 3 or 4), wherein if the value of b is more than 1, at least two R are substituted on a mother ring_aAt least two R_aCan be selected from the same group or different groups, and can be selected and adjusted by the skilled in the art according to the actual needs; the meanings of the following references are the same as those of the above description, and are not described in detail;

in the formula (I), b is an integer of 2 to 4 (e.g., 2, 3 or 4), R_aAre not connected with each other to form a ring;

in the formula (I), L is any one selected from a single bond, chain alkylene of C1-C12, cycloalkylene of C3-C12, substituted or unsubstituted C6-C30 arylene and substituted or unsubstituted C3-C30 heteroarylene;

in the formula (I), Ar is any one selected from cyano, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl;

R_ain L and Ar, the substituted groups are respectively and independently selected from one or the combination of at least two of halogen, cyano, nitro, hydroxyl, C1-C12 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 fused ring heteroaryl, wherein the halogen comprises fluorine, chlorine, bromine, iodine and the like; monocyclic aryl means that the molecule contains one or at least two phenyl groups, when the molecule containsWhen there are at least two phenyl groups, the phenyl groups are independent of each other and are linked by a single bond, such as phenyl, biphenylyl, terphenylyl, and the like, for example; the condensed-ring aromatic group means that at least two benzene rings are contained in the molecule, but the benzene rings are not independent of each other, but common ring sides are condensed with each other, and exemplified by naphthyl, anthryl, pyrenyl, perylenyl, perylene, etc,A group, etc.; monocyclic heteroaryl means that the molecule contains at least one heteroaryl group, and when the molecule contains one heteroaryl group and other groups (e.g., aryl, heteroaryl, alkyl, etc.), the heteroaryl and other groups are independent of each other and are linked by a single bond, illustratively pyridine, furan, thiophene, etc.; the fused ring heteroaryl group means a fused group of at least one phenyl group and at least one heteroaryl group, or a fused group of at least two heteroaryl rings, illustratively quinoline, isoquinoline, phenanthroline, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene, and the like.

In the present invention, Ca-Cb represents that the group has a carbon number of a-b, for example, C1-C10 represents that the group has a carbon number of 1-10, it being noted that the carbon number does not include the carbon number of the substituent.

The C1-C12 can be C2, C3, C4, C5, C6, C7, C8, C9, C10 and C11.

The C3-C12 can be C4, C5, C6, C7, C8, C9, C10 and C11.

The C6-C60 can be C12, C14, C16, C18, C20, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, C48, C50, C52, C54, C56, C58 and the like.

The C3-C60 can be C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, C48, C50, C52, C54, C56, C58 and the like.

The C3-C30 can be C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, C30 and the like.

The C6-C30 can be C8, C10, C12, C14, C16, C18, C20, C26, C28, C30 and the like.

The C6-C40 can be C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38 and the like.

The C1-C10 can be C2, C3, C4, C5, C6, C7, C8, C9 and the like.

The C1-C6 can be C2, C3, C4, C5 and the like.

In the present invention, the heteroatom in the "heteroaryl" referred to is generally selected from any one of N, O or S or a combination of at least two thereof; when the term "heteroaryl" is used hereinafter, the heteroatom is selected as the same as that herein, and thus, the detailed description thereof is omitted.

The compound provided by the invention takes pyridotriazole as a mother ring, a new electron transport material is formed by introducing cyano, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, and the formed new material has good molecular dipole moment and evaporation film-forming property, so that the compound has high electron injection and migration performance.

The compound provided by the invention can be used in an organic electroluminescent device to improve the electron injection and migration efficiency of the device, thereby improving the luminous efficiency of the device and reducing the starting voltage of the device.

Preferably, said R is_aIndependently selected from any one of substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl;

preferably, said R is_aIndependently selected from any one of substituted or unsubstituted C6-C40 aryl.

Preferably, said R is_aIndependently selected from any one of the following substituted or unsubstituted groups:

wherein denotes the attachment site.

In the present invention, the connecting site with the mother ring is denoted, and the meaning of the reference is the same as that of the connecting site, if appearing later, and will not be described later.

Preferably, said R is_aIndependently selected from any one of the following substituted or unsubstituted groups:

preferably, b is 0 or 1.

Preferably, L is selected from any one of substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C3-C30 heteroarylene;

preferably, L is selected from substituted or unsubstituted C6-C30 arylene.

Preferably, L is selected from substituted or unsubstituted C6-C18 arylene.

Preferably, the L is selected from any one of the following substituted or unsubstituted groups:

wherein denotes the attachment site.

Preferably, the L is selected from any one of the following substituted or unsubstituted groups:

wherein denotes the attachment site.

Preferably, Ar is any one selected from substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C3-C30 heteroaryl.

Preferably, Ar is selected from any one of substituted or unsubstituted C3-C30 heteroaryl.

Preferably, Ar is selected from any one of substituted or unsubstituted C3-C30 electron-deficient heteroaryl.

In the present invention, the "electron-deficient heteroaryl group" is an "electron-deficient group", wherein the "electron-deficient group" means a group having a Hammett value of more than 0.6, and the larger the Hammett value is, the more electronegative it is. The Hammett value is a representation of the charge affinity for a particular group and is a measure of the electron withdrawing group (positive Hammett value) or electron donating group (negative Hammett value). The Hammett equation is described In more detail In Thomas H.Lowry and Kathelen Schueler Richardson, "mechanics and Theory In Organic Chemistry", New York,1987, 143-.

Preferably, Ar is selected from any one of (Hy-1) - (Hy-4) groups:

(Hy-1) wherein Y is as defined above₁、Y₂、Y₃、Y₄、Y₅And Y₆Each independently selected from the group consisting of CR or N atoms, and Y₁、Y₂、Y₃、Y₄、Y₅And Y₆At least one of them is an N atom;

(Hy-2) wherein Z is₁、Z₂、Z₃、Z₄And Z₅Each independently selected from the group consisting of CR or N atoms, and Z₁、Z₂、Z₃、Z₄And Z₅At least one of them is an N atom;

(Hy-3) wherein Z is₆、Z₇、Z₈、Z₉、Z₁₀、Z₁₁、Z₁₂And Z₁₃Each independently selected from the group consisting of CR or N atoms, and Z₆、Z₇、Z₈、Z₉、Z₁₀、Z₁₁、Z₁₂And Z₁₃At least one of them is an N atom;

(Hy-4) wherein Y is as defined above₇、Y₈、Y₉、Y₁₀、Y₁₁、Y₁₂And Y₁₃Each independently selected from the group consisting of CR or N atoms, and Y₇、Y₈、Y₉、Y₁₀、Y₁₁、Y₁₂And Y₁₃At least one of them is an N atom;

r is independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, chain alkyl of C1-C12, alkoxy of C1-C12, cycloalkyl of C3-C12, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, and the substituted group is selected from any one of halogen, chain alkyl of C1-C10, C3-C10 cycloalkyl, C2-C10 alkenyl, C1-C6 alkoxy, C1-C6 thioalkoxy, C6-C30 monocyclic aryl, C10-C30 fused ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 fused ring heteroaryl;

wherein denotes a ligation site;

preferably, (Hy-1) wherein Y is₁、Y₂、Y₃、Y₄、Y₅And Y₆Wherein 2 to 4 (e.g., 2, 3 or 4) are N atoms.

Preferably, (Hy-2) wherein Z is₁、Z₂、Z₃、Z₄And Z₅Wherein 2 to 4 (e.g., 2, 3 or 4) are N atoms.

Preferably, (Hy-3) wherein Z is₆、Z₇、Z₈、Z₉、Z₁₀、Z₁₁、Z₁₂And Z₁₃Wherein 2 to 4 (e.g., 2, 3 or 4) are N atoms.

Preferably, (Hy-4) wherein Y is₇、Y₈、Y₉、Y₁₀、Y₁₁、Y₁₂And Y₁₃Wherein 2 to 4 are N atoms.

Preferably, Ar is selected from any one of the following substituted or unsubstituted groups:

preferably, Ar is selected from any one of the following groups:

wherein denotes a ligation site;

preferably, Ar is selected from

As a preferred technical scheme of the invention, the compound has a structure shown in C1-C270 (see the table 1 in the foregoing), has high electron injection and migration performance, and can be used as an electron transport layer material for an organic electroluminescent device; wherein, in order to clearly show the specific structure of the compound, the general formula of the compound is marked as the formula (I-1) in the specification, 1, 2, 3 and 4 have no specific meaning in the formula (I-1), but simply represent R_aThe group being substituted at a particular position of the parent ring when R in Table 1_aWhen all the groups are selected from hydrogen, the default value of b is 0, and when one or more R in the table 1_aWhen the group is not selected from hydrogen, the value of b and R are defaulted_aThe number of groups not selected from hydrogen is the same.

It is a second object of the present invention to provide an application as described in the first object as a material for an electron transport layer in an organic electroluminescent device.

It is a further object of the present invention to provide an organic electroluminescent device comprising a first electrode, a second electrode and an organic layer between the first electrode and the second electrode, the organic layer containing a compound according to one of the objects.

More specifically, the organic electroluminescent device will be described in detail.

An OLED (organic electroluminescent device) includes first and second electrodes, and an organic material layer between the electrodes. The organic material may in turn be divided into a plurality of regions. For example, the organic material layer may include a hole transport region, a light emitting layer, and an electron transport region.

In a specific embodiment, a substrate may be used below the first electrode or above the second electrode. The substrate is a glass or polymer material having excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a Thin Film Transistor (TFT) may be provided on a substrate for a display.

The first electrode may be formed by sputtering or depositing a material used as the first electrode on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), or any combination thereof may be used. When the first electrode is used as a cathode, a metal or an alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof can be used.

The organic material layer may be formed on the electrode by vacuum thermal evaporation, spin coating, printing, or the like. The compound used as the organic material layer may be an organic small molecule, an organic large molecule, and a polymer, and a combination thereof.

The hole transport region is located between the anode and the light emitting layer. The hole transport region may be a Hole Transport Layer (HTL) of a single layer structure including a single layer containing only one compound and a single layer containing a plurality of compounds. The hole transport region may also be a multilayer structure including at least one of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), and an Electron Blocking Layer (EBL).

The material of the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylenevinylene, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphorsulfonic acid (Pani/CSA), polyaniline/poly (4-styrenesulfonate) (Pani/PSS), aromatic amine derivatives such as compounds shown below in HT-1 to HT-34; or any combination thereof.

The hole injection layer is located between the anode and the hole transport layer. The hole injection layer may be a single compound material or a combination of a plurality of compounds. For example, the hole injection layer may employ one or more compounds of HT-1 to HT-34 described above, or one or more compounds of HI-1 to HI-3 described below; one or more of the compounds HT-1 to HT-34 may also be used to dope one or more of the compounds HI-1 to HI-3 described below.

The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit different wavelength spectra, and may also include a Host material (Host). The light emitting layer may be a single color light emitting layer emitting a single color of red, green, blue, or the like. The single color light emitting layers of a plurality of different colors may be arranged in a planar manner in accordance with a pixel pattern, or may be stacked to form a color light emitting layer. When the light emitting layers of different colors are stacked together, they may be spaced apart from each other or may be connected to each other. The light-emitting layer may be a single color light-emitting layer capable of emitting red, green, blue, or the like at the same time.

According to different technologies, the luminescent layer material can be different materials such as fluorescent electroluminescent material, phosphorescent electroluminescent material, thermal activation delayed fluorescent luminescent material, and the like. In an OLED device, a single light emitting technology may be used, or a combination of a plurality of different light emitting technologies may be used. These technically classified different luminescent materials may emit light of the same color or of different colors.

In one aspect of the invention, the light-emitting layer employs a fluorescent electroluminescence technique. The luminescent layer fluorescent host material may be selected from, but not limited to, the combination of one or more of BFH-1 through BFH-17 listed below.

In one aspect of the invention, the light-emitting layer employs a fluorescent electroluminescence technique. The luminescent layer fluorescent dopant may be selected from, but is not limited to, combinations of one or more of BFD-1 through BFD-12 listed below.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The host material of the light emitting layer is selected from, but not limited to, one or more of GPH-1 to GPH-80.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light emitting layer can be selected from, but is not limited to, one or more of GPD-1 to GPD-47 listed below.

Wherein D is deuterium.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light emitting layer thereof may be selected from, but not limited to, a combination of one or more of RPD-1 to RPD-28 listed below.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light-emitting layer can be selected from, but is not limited to, one or more of YPD-1 to YPD-11 listed below.

The organic electroluminescent device of the present invention includes an electron transport region between the light emitting layer and the cathode. The electron transport region may be an Electron Transport Layer (ETL) of a single-layer structure including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing a plurality of compounds. The electron transport region may also be a multilayer structure including at least one of an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), and a Hole Blocking Layer (HBL).

The electron transport region may also be formed using the compound of the present invention for a multilayer structure including at least one of an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), and a Hole Blocking Layer (HBL), although the material of the electron transport region may also be combined with one or more of ET-1 to ET-57 listed below.

An electron injection layer may also be included in the device between the electron transport layer and the cathode, the electron injection layer material including, but not limited to, combinations of one or more of the following:

Liq、LiF、NaCl、CsF、Li₂O、Cs₂CO₃、BaO、Na、Li、Ca。

compared with the prior art, the invention has the following beneficial effects:

the compound provided by the invention has higher electron injection and migration performance; the compound is used in an organic electroluminescent device, so that the electron injection and migration efficiency of the device can be improved, the luminous efficiency of the device can be improved, and the starting voltage of the device can be reduced.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Compounds of synthetic methods not mentioned in the present invention are all starting products obtained commercially. The solvents and reagents used in the present invention, such as ethyl acetate, sodium sulfate, toluene, tetrahydrofuran, dichloromethane, potassium carbonate, and other chemical reagents, can be purchased from domestic chemical product markets, such as Shanghai Tantake technology, Inc., and Xilongchemical, Inc.

The present invention will be described in detail below by way of examples, and the compounds of the present invention can be prepared by reference to the general synthetic formulae shown below.

Synthesizing a general formula I:

the first step is as follows: 2-halogenated bromopyridine and hydrazine hydrate are subjected to substitution reaction to generate an intermediate M1-1; a second step of condensation reaction of the intermediate M1-1 and chlorinated aldehydes (such as chlorinated benzaldehyde for example) to generate an intermediate M1-2; thirdly, oxidizing the intermediate M1-2 to generate an intermediate M1-3 under the action of iodobenzene acetate; fourthly, the intermediate M1-3 generates an intermediate M1-4 through Suzuki coupling reaction; fifthly, generating a target product Cx by the intermediate M1-4 through a Suzuki coupling reaction;

wherein Ra, b, L and Ar have the same limitations as defined in claim 1, and X is selected from halogen.

When Ar is cyano, the compound can also be prepared by reference to the following synthetic formula II:

synthesizing a general formula II:

the synthesis of the general formula two differs from the synthesis of the general formula one only in that the chlorinated aldehydes are replaced by cyano-substituted aldehydes in the second stage, and the remaining synthesis processes are essentially identical.

The analytical detection of the intermediates and compounds in the present invention was carried out using a ZAB-HS type mass spectrometer (Micromass, UK).

Synthesis example 1

Synthesis of Compound C11

(1) Preparation of Compound 1-1

2-iodo-5-bromopyridine (283g, 1mol), hydrazine hydrate (313g, 5mol, 80%) were added to a flask containing 1.5L of pyridine at room temperature, heated to reflux with stirring for about 12 hours, and the reaction was completed by TLC. Cooling to room temperature, decompressing, rotary evaporating to remove solvent to obtain white solid 1-1, washing with petroleum ether, suction filtering, drying in the air and then directly putting into the next step for reaction.

(2) Preparation of Compounds 1-2

The crude compound 1-1, 4-chlorobenzaldehyde (210g, 1.5mol) obtained in the above step was added to a flask containing ethanol (3L), and after replacement of nitrogen, the reaction was refluxed with stirring for about 15 hours, and the end point of the reaction was monitored by TLC. The temperature is reduced to room temperature, the obtained solid is filtered by suction, ethanol and petroleum ether are respectively leached, and the compound 1-2(250g, yield 81%) is obtained after drying.

(3) Preparation of Compounds 1-3

After the compound 1-2(247.2g, 0.8mol) was added to a flask containing ethanol (3L) and nitrogen was replaced, an ethanol solution containing iodobenzene acetate (322g, 1mol) was slowly dropped at room temperature, and the reaction was continued at room temperature for about 6 hours with monitoring of the end point of the reaction by TLC. Cooling to room temperature, rotary evaporating under reduced pressure to remove solvent, dissolving the crude compound with DCM, purifying by column chromatography, and drying to obtain compound 1-3(128g, yield 52%).

(4) Preparation of Compounds 1-4

Compound 1-3(30.7g, 100mmol), 9-phenanthreneboronic acid (24.4g, 110mmol), and potassium carbonate (41.4g, 300mmol) were added to a toluene/ethanol/water (300/100/100mL) flask, nitrogen was replaced, and Pd (PPh) was added₃)₄(1.2g, 1 mmol). After the addition was completed, the reaction was refluxed for about 4 hours under stirring under nitrogen atmosphere, and the end point of the reaction was monitored by TLC. Cooling to room temperature, separating, extracting water phase with ethyl acetate, mixing organic phases, drying with anhydrous sodium sulfate, filtering, evaporating under reduced pressure to remove solvent, and performing column chromatography to obtain crude productPurification yielded compounds 1-4(36g, 89% yield).

(5) Preparation of Compounds 1-5

Compound 1-4(20.2g, 50mmol), pinacol diboron ester (19g, 75mmol) and potassium acetate (14.7g, 150mmol) were charged into a flask containing 1, 4-dioxane (300mL), and after replacing nitrogen with stirring at room temperature, palladium acetate (224mg, 1mmol) and SPhos (820mg, 2mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 10 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, the mixture was separated with water and dichloromethane, the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compounds 1 to 5(21g, yield 83%).

(6) Preparation of Compound C11

Compounds 1-5(10g, 20mmol), 2-chloro-4, 6-diphenyl-1, 3, 5-triazine (5.4g, 20mmol), potassium carbonate (8.3g, 60mmol), pd (dppf) Cl₂(146mg, 0.2mmol) was added to a flask containing 150mL tetrahydrofuran and 30mL water, the nitrogen was replaced and the reaction was heated to reflux under nitrogen for about 8 hours and TLC indicated completion of the reaction. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C11(8.9g, yield 74%). Calculated molecular weight: 602.22, found m/z: 602.2.

synthesis example 2

Synthesis of Compound C47

The only difference from the preparation method of synthesis example 1 was that 4-chlorobenzaldehyde was replaced by 3-chlorobenzaldehyde, 9-phenanthreneboronic acid was replaced by 2-boronic acid-9, 9-dimethylfluorene, and the molecular weight calculated value of the obtained compound C47: 618.25, found m/z: 618.3.

synthesis example 3

Synthesis of Compound C69

(1) Preparation of Compounds 3-4

The compound 3-4 is prepared by a synthesis method similar to the compound 1-4, except that the raw material 2-iodo-5-bromopyridine is replaced by 2, 6-dibromopyridine, and 9-phenanthreneboronic acid is replaced by 3-phenylboronic acid.

(2) Preparation of Compound C69

Compound 3-4(7.6g, 20mmol), 2, 4-diphenyl-6 (4-boronylphenyl) -1,3, 5-triazine (8.7g, 20mmol), potassium carbonate (8.3g, 60mmol), pd2(dba)3(184mg, 0.2mmol), Sphos (164mg, 0.4mmol) were added to a flask containing 150mL1, 4-dioxane and 15mL water, the nitrogen was replaced and the reaction was heated under reflux under nitrogen atmosphere for about 10 hours, and TLC showed completion of the reaction. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to obtain compound C69(9.1g, yield 70%). Calculated molecular weight: 654.25, found m/z: 654.2.

synthesis example 4

Synthesis of compound C93:

the preparation method differs from synthesis example 1 only in that 4-chlorobenzaldehyde is replaced by 4-cyanobenzaldehyde, 9-phenanthreneboronic acid is replaced by 2-boronic acid-9, 9-spirobifluorene, and the calculated molecular weight of the obtained compound C93 is as follows: 534.18, found m/z: 534.2.

synthesis example 5

Synthesis of Compound C158

The preparation method differed from synthesis example 3 only in that 3-phenylphenylboronic acid was replaced with 2-boronic acid-9, 9-spirobifluorene, 2, 4-diphenyl-6 (4-boronylphenyl) -1,3, 5-triazine was replaced with 4-cyanophenylboronic acid, and the calculated molecular weight of the resulting compound C158 was: 610.22, found m/z: 610.2.

synthesis example 6

Synthesis of Compound C245

The preparation method differed from synthetic example 4 only in that 2-chloro-4, 6-diphenyl-1, 3, 5-triazine was replaced with 9-bromo-10 (2-naphthyl) anthracene, and the molecular weight calculated value of the obtained compound C245: 522.18, found m/z: 522.2.

example 1

This example provides an organic electroluminescent device, which is prepared as follows:

ultrasonically treating the glass plate coated with the ITO transparent conducting layer in a commercial cleaning agent, washing the glass plate in deionized water, ultrasonically removing oil in an acetone-ethanol mixed solvent, baking the glass plate in a clean environment until the water is completely removed, cleaning the glass plate by using ultraviolet light and ozone, and bombarding the surface by using low-energy solar beams;

placing the glass substrate with the anode in a vacuum chamber, and vacuumizing to less than 1 × 10^-5Pa, vacuum evaporating a hole injection material HI-3 on the anode layer film to form a hole injection layer, wherein the evaporation rate is 0.1nm/s, and the evaporation film thickness is 10 nm;

evaporating HT-4 on the hole injection layer in vacuum to serve as a first hole transport layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 40 nm;

evaporating HT-14 on the first hole transport layer in vacuum to serve as a second hole transport layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 10 nm;

a luminescent layer of the device is vacuum evaporated on the second hole transport layer, the luminescent layer comprises a main material and a dye material, the evaporation rate of the main material BFH-4 is adjusted to be 0.1nm/s, the evaporation rate of the dye BFD-4 is set in a proportion of 5%, and the total film thickness of evaporation is 20nm by using a multi-source co-evaporation method;

vacuum evaporating ET-17 on the luminescent layer to be used as a hole blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness is 5 nm;

evaporating compounds C11 and ET-57 as electron transport layers on the hole blocking layer by a multi-source co-evaporation method, adjusting the evaporation rate of the compound C11 to be 0.1nm/s, setting the evaporation rate to be 100% of the evaporation rate of the ET-57 (the evaporation rate of the compounds C11 and ET-57 is 1:1), and setting the total film thickness of evaporation to be 23 nm;

LiF with the thickness of 1nm is vacuum-evaporated on the Electron Transport Layer (ETL) to be used as an electron injection layer, and an Al layer with the thickness of 80nm is used as a cathode of the device.

Examples 2 to 6

The only difference from example 1 was that C11 was sequentially replaced with the compounds synthesized in synthesis examples 2 to 6.

Comparative example 1

The only difference from example 1 is that C11 was replaced with D-1.

Comparative example 2

The only difference from example 1 is that C11 is replaced by D-2.

And (3) performance testing:

the driving voltage and current efficiency of the organic electroluminescent devices prepared in examples 1 to 6 and comparative examples 1 to 2 were measured at the same brightness using a Photo radiometer model PR 750 from Photo Research, a brightness meter model ST-86LA (photoelectric instrument factory, university of beijing) and a Keithley4200 test system. Specifically, the voltage was raised at a rate of 0.1V per second, and it was determined that the luminance of the organic electroluminescent device reached 1000cd/m²The current density is measured at the same time as the driving voltage; the ratio of the brightness to the current density is the current efficiency;

the results of the performance tests are shown in table 2.

TABLE 2

	Electron transport material	Required luminance (cd/m)2)	Voltage (V)	Current efficiency (cd/A)
					Example 1	Compound C11	1000.00	3.97	9.01
Example 2	Compound C47	1000.00	3.81	9.17
					Example 3	Compound C69	1000.00	3.92	9.13
Example 4	Compound C93	1000.00	3.78	9.32
					Example 5	Compound C158	1000.00	3.73	9.36
Example 6	Compound C245	1000.00	3.88	9.21
					Comparative example 1	Compound D-1	1000.00	4.56	7.78
Comparative example 2	Compound D-2	1000.00	4.73	8.04

As can be seen from table 1, in the case where other materials are the same in the structure of the organic electroluminescent device, the organic electroluminescent devices provided in embodiments 1 to 6 of the present invention have higher current efficiency and lower driving voltage.

The driving voltages of the devices using the compounds of comparative examples 1 and 2 as electron transport materials were 4.56V and 4.73V, respectively, and the current efficiencies were 7.78cd/a and 8.04cd/a, respectively, which are large differences in performance compared to the devices of examples. The reason is probably that the compound adopts pyrido triazole to form a new electron transport material by matching electron-deficient groups such as triazine, pyrimidine, quinazoline, cyano and the like through bridging, and compared with a molecule formed by the comparative example of molecules through aza-phenanthrene triazole or isoquinoline triazole bridging triazine, the molecule has more suitable molecular dipole moment, so that the electron injection capability is stronger. In addition, the molecule of the invention has good evaporation film-forming property, and can be in close contact with an adjacent organic layer when forming a device, thereby being more beneficial to the improvement of electron mobility.

Therefore, the new electron transport material formed by matching the electron deficient groups such as the pyridotriazole and the triazine, the pyrimidine, the quinazoline, the cyano group and the like with the electron deficient groups through bridging has higher electron injection and migration performance, so that the device has higher current efficiency and lower driving voltage.

The experimental data show that the novel organic material is an organic luminescent functional material with good performance as an electron transport material of an organic electroluminescent device, and has wide application prospect.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.